The techies going to work at Comcast Corp.'s new Center City tower might want to forget about slacking off when the boss goes home. He may be right upstairs.

Comcast chief executive Brian Roberts and his wife, Aileen, have purchased a floor of three condo units in the 60-story Comcast Technology Center, which is rising next to the Philadelphia-based company's existing headquarters building.

The Robertses' units are on the 45th floor of the 1800 Arch St. tower, sandwiched between Comcast offices and the Four Seasons hotel planned for the building's top floors, according to records filed with the city.

The units will be Four Seasons Residences condominiums that will be managed by the Four Seasons, Comcast senior executive vice president David Cohen said in an interview this week.

Roberts was not available to comment on the transaction, Comcast spokesman John Demming said.

If the Robertses reside in the units themselves, their living situation will recall that of a past Philadelphia media baron: former Inquirer publisher James "Colonel" Elverson Jr., who made a home on the 12th and 13th floors of the newspaper building he had constructed at 400 N. Broad St. in the 1920s.

In 1990s Atlanta, meanwhile, media mogul Ted Turner lived in a penthouse atop the CNN Center tower before moving to a larger residence on the upper floors of a nearby building, where his current businesses are located.

The Robertses bought their Comcast Technology Center units, encompassing 14,663 square feet, for $14.3 million in December from an affiliate of Liberty Property Trust, which is developing the building for the cable/entertainment company, according to records filed with the city.

The Norman Foster-designed tower will be the tallest building in the United States outside New York or Chicago when it is completed in 2018. Planned for the building are offices and labs for Comcast's growing workforce of technologists, engineers and software architects, as well as studios for its local NBC and Telemundo affiliates. The Four Seasons hotel will begin on the tower's 48th floor.

The Robertses' three units are the building's only for-sale residences, according to a condominium agreement filed with the city. Their units also offer access to a 5,200-square-foot terrace on the south side of the building.

The purchase follows the Robertses' sale in April of a 10 Rittenhouse two-story residence in the condo tower at 130 S. 18th St. to Richard Green, chief executive of Conshohocken-based Firstrust Bank, for $9.38 million, according to records filed with the city. That dwelling encompasses 9,130 square feet, according to real-estate-listing service Trend.

The Robertses never occupied that home, Cohen said. They are known to be longtime residents of Chestnut Hill.